Digital printers and copiers are familiar in offices. Many models of such printers and copiers (broadly, “output devices,” meaning any machine which outputs a sheet) are designed to work with “finishing modules” which accept and finish (e.g., collate, staple, fold, hole-punch, etc.) sheets emitted by the printer. The finishing module is typically an optional, add-on device, i.e., the printer itself is capable of functioning without the finishing module.
The transfer of a sheet output by the printer and acceptance of the sheet by the finishing module must be made with minimal risk of damage to the sheet. Thus, the physical interface between the printer and the finishing module must be designed carefully. Further, if there is a jam or other malfunction in or near the interface, it is desirable to design a configuration which allows easy opening of the interface, so that a jammed sheet may be removed, and a reliable re-closing of the interface.